Biology and culture of siganids

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Abstract

A 53-page monograph updating AQD's 1990 publication of the same title. The book includes siganid morphology, distribution and ecology; reproduction; fisheries; diseases and parasites; genetics. It also covers larval culture; fry and fingerling production; nutrition and feeds; and problem areas in aquaculture.

Aquaculture in Malaysia is experiencing rapid growth. Total production in 1992 amounted to 79,699 tons valued at RM 207.4 million. These figures are 23% and 25% higher than the previous year's. Semi-culture of the cockle Anadara granosa was still predominant, contributing about 70% of the total output. Culture and production of the oyster Crassostrea iredalei is still insignificant. Sea bass Lates calcarifer constituted over 80% of the production from marine cages. Cage culture of grouper Epinephelus sp., snapper Lutjanus sp. and pompano Trachinotus blochii were also done in much smaller scale. The mangrove snapper Lutjanus argentimaculatus was recently spawned in captivity and larvae and juveniles were produced. In 1992, the tiger shrimp Penaeus monodon constituted about 87% of brackishwater pond production. Pond culture of the white shrimp P. merguiensis and the mudcrab Scylla sp. is at the experimental stage. Red tilapia hybrid was the major freshwater species cultured in cages, with 1,486 tons harvested in 1992. Freshwater pond production was valued at RM 100.85 million, 22% of which was due to the eel Anguilla japonica. Production of freshwater ornamental fishes is also becoming significant. Other exotic species recently bred and cultured are the African catfish Clarias gariepinus and the pacu Piaractus brachypomus. The indigenous freshwater catfish Mystus nemurus and carp Probarbus julleini have recently been bred in captivity and cultured experimentally. Lately, there have been attempts to culture non-conventional species such as the bullfrog Rana catesbeiana, the soft-shell turtle Trionyx sinensis, and aquatic ornamental plants.

Coastal aquaculture in Thailand has expanded rapidly in both area and production in the last decade. The important cultured species are the shrimps (Penaeus monodon and P. merguiensis), sea bass Lates calcarifer, groupers Epinephelus malabaricus and E. tauvina, green mussel Perna viridis, horse mussel Modiolus senhausenii, blood cockles Anadara granosa and A. nodifera and the oysters Crassostrea belcheri, C. lugubris and Saccostrea commercialis. The total production from coastal aquaculture in 1991 was 230,444 tons, consisting of 70.3% shrimp, 28.8% mollusks, and 0.9% fishes. The seaweeds Gracilaria spp., pearl oysters, scallops, and abalones are cultured on a pilot scale in some places. Hatchery technologies have recently been developed for groupers, oysters, scallops, and abalones. Expanded aquaculture has had some adverse effects on the environment and has also suffered from the environmental changes and conflicts due to other sectors using the same water and other resources.

Aquaculture is regarded as the most promising source of protein food in the years ahead. Milkfish and Nile tilapia are the major fishes now produced but groupers, sea bass, rabbitfish, red snappers, carps, and catfishes are grown by some farmers. The tiger shrimp is still the most important cultured crustacean, but white shrimps and mudcrabs also have great potential. Oysters and mussels are produced in considerable amounts. Mariculture of the seaweed Eucheuma is now a well established industry, and the pond culture of Gracilaria for agar extraction is beginning to take off.